PHP 5.6.0RC3 is available


PHP的进程控制支持实现了Unix方式的进程创建, 程序执行, 信号处理以及进程的中断。 进程控制不能被应用在Web服务器环境,当其被用于Web服务环境时可能会带来意外的结果。

这份文档用于阐述每个进程控制函数的通常用法。关于Unix进程控制的更多信息建议您查阅 系统文档中关于fork(2),waitpid(2),signal(2)等的部分或更全面的参考资料比如 《Unix环境高级编程》(作者:W. Richard Stevens,Addison-Wesley出版)。

PCNTL现在使用了ticks作为信号处理的回调机制,ticks在速度上远远超过了之前的处理机制。 这个变化与“用户ticks”遵循了相同的语义。您可以使用declare() 语句在程序中指定允许发生回调的位置。这使得我们对异步事件处理的开销最小化。在编译PHP时 启用pcntl将始终承担这种开销,不论您的脚本中是否真正使用了pcntl。

有一个调整是PHP 4.3.0之前的所有pcntl脚本要使其工作,要么在期望允许回调的(代码)部分使用 declare() ,要么使用declare()新的全局语法 使其在整个脚本范围有效。

Note: 此扩展在 Windows 平台上不可用。

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User Contributed Notes 1 note

sean dot kelly at mediatile dot com
2 years ago
The following statement left me searching for answers for about a day before I finally clued in:

"Process Control should not be enabled within a web server environment and unexpected results may happen if any Process Control functions are used within a web server environment."

At least for PHP 5.3.8 which I am using, and who knows how far back, it's not a matter of "should not", it's "can not". Even though I have compiled in PCNTL with --enable-pcntl, it turns out that it only compiles in to the CLI version of PHP, not the Apache module. As a result, I spent many hours trying to track down why function_exists('pcntl_fork') was returning false even though it compiled correctly. It turns out it returns true just fine from the CLI, and only returns false for HTTP requests. The same is true of ALL of the pcntl_*() functions.
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